Find out Gamma for Multiline TRL

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Md. Imtiaz Kamrul

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Sep 13, 2021, 12:33:37 AMSep 13
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Hello everyone, It may appear to be a simple question, but I am having difficulty implementing the multilne calibration.

I have two Line standard files, as well as thru, reflect, and DUT files. But how do I get a gamma file for calibration? Is there anyone who has any idea on this?

Thank you very much to everyone.

Denz Choe

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Sep 13, 2021, 2:34:43 AMSep 13
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after calibration you can extract the Gamma properties via CalObj.gamma.real if you use the following calibration:

Md. Imtiaz Kamrul

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Sep 13, 2021, 3:15:12 AMSep 13
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But without gamma_f & gamma_r file, how can I run the calibration?
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Denz Choe

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Sep 13, 2021, 4:03:37 AMSep 13
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Ah ok I understand your source of confusion of the gamm_f and gamm_r terms now if you are following

You can search in the forum for 'switch terms' to understand further what it means.
Or you can jump straight into my discussion for a similar case like you I had before and how to extract it from the VNA. Vince West image will guide you how. 

TLDR, if you are performing a 2nd tier calibration (after your VNA cables are calibrated); you do not need the "switch_terms" values.





On Monday, September 13, 2021 at 3:47:21 PM UTC+8 Denz Choe wrote:
See this 

and look for this

Capture3.JPG

Md. Imtiaz Kamrul

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Sep 13, 2021, 7:08:37 AMSep 13
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Thank you so much.

Md. Imtiaz Kamrul

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Sep 13, 2021, 7:17:50 AMSep 13
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I have another query. Can you please help me!  Is it possible to plot the results (S11 & S21) of calibration before and after using scikit-rf? I can't seem to find anything on the guideline?

On Monday, 13 September 2021 at 17:03:37 UTC+9 kinkha...@gmail.com wrote:

Denz Choe

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Sep 14, 2021, 8:28:20 AMSep 14
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something is weird with my Google Groups. I did not get notification of this message.
Sorry about that. I hoped Julien already answered your query. 

Else, results of before and after calibration can be easily done by copying the DUT Network file to a dummy Network file and compare it with after calibration.
Everytime you apply Calibration it generates returns a new Network Obj.

    meas_uncal = nosw_mstrip_line3
    meas_dut1 = cal_trl_new1.apply_cal(meas_uncal)


Now you have 2 Network files. Just plot them to your liking to see the difference.

Md. Imtiaz Kamrul

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Sep 14, 2021, 9:39:49 PMSep 14
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Yes, thank you very much for all of your support.
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